injection parameter of HDPE material
suggest set heating temperature
feeding zoneof Barrel temperature 30～50°C (50°C)
Zone 1 160 ~ 250 ° C (200 ° C)
Zone 2 200～300°C (210°C)
Zone 3 220 ~ 300 ° C (230 ° C)
Zone 4 220 ~ 300 ° C (240 ° C)
District 5 220 ~ 300 ° C (240 ° C)
Nozzle 220 ~ 300 ° C (240 ° C)
The temperature in parentheses is recommended as the basic setting, the stroke utilization is 35% and 65%, and the ratio of module flow length to wall thickness is 50:1 to 100:1.
Melt temperature 220～280°C
Barrel constant temperature 220 ° C
Mold temperature 20～60°C
Injection pressure has good flow performance, avoiding excessive injection pressure of 80 ~ 140MPa (800 ~ 1400bar);
Except for some thin-walled packaging containers up to 180MPa (1800bar)
Holding pressure The degree of shrinkage is high, it takes a long time to hold the product. The dimensional accuracy is the key factor, about 30% to 60% of the injection pressure.
Back pressure 5～20MPa (50～200bar); where the back pressure is too low, it is easy to cause product weight and dispersion unevenness.
Injection speed requires high injection speed for thin-walled packaging containers. Medium injection speeds are often suitable for other types of plastic products.
Screw speed High screw speed (line speed 1.3m/s) is permissible, as long as the plasticizing process is completed before the end of the cooling time; the screw torque requirement is low.
Metering stroke 0.5 ~ 4D (minimum ~ maximum); 4D metering stroke is very important to provide a long enough residence time for the melt
Residual material amount 2～8mm, depending on metering stroke and screw diameter
Pre-drying is not required; if the storage conditions are not good, it can be dried at 80 ° C for 1 h.
Recovery rate can reach 100% recycling
Shrinkage 1.2～2.5%; easy to twist; high degree of shrinkage; no shrinkage after 24h (shrinkage after molding)
Gate system Point gate; heated hot runner, insulated hot runner, in-situ sleeve; relatively small cross-sectional area, sufficient for thin section products
No special cleaning work is required for other machine materials during the machine shutdown period; PE temperature rise resistance
Barrel equipment Standard screw, standard three-stage screw; special for packaging container products, mixing section and shear section geometry (L: D=25:1), straight-through nozzle, check valve.